diff --git a/apps/zasm/tests/geninstrs.py b/apps/zasm/tests/geninstrs.py
index 58e986a..dfb5837 100755
--- a/apps/zasm/tests/geninstrs.py
+++ b/apps/zasm/tests/geninstrs.py
@@ -14,6 +14,7 @@ argspecTbl = {
     'A': "A",
     'B': "B",
     'C': "C",
+    'k': "(C)",
     'D': "D",
     'E': "E",
     'H': "H",
@@ -129,6 +130,8 @@ def main():
         if n == 'BIT':
             # we only want to keep 1, 2, 4
             args1 = args1[:3]
+        if n == 'IM':
+            args1 = [0, 1, 2]
         if args1:
             for arg1 in args1:
                 args2 = genargs(a2)
diff --git a/apps/zasm/zasm.asm b/apps/zasm/zasm.asm
index 696cd82..e9c8f73 100644
--- a/apps/zasm/zasm.asm
+++ b/apps/zasm/zasm.asm
@@ -2,9 +2,9 @@
 
 ; *** Consts ***
 ; Number of rows in the argspec table
-ARGSPEC_TBL_CNT		.equ	28
+ARGSPEC_TBL_CNT		.equ	29
 ; Number of rows in the primary instructions table
-INSTR_TBL_CNT		.equ	108
+INSTR_TBL_CNT		.equ	114
 ; size in bytes of each row in the primary instructions table
 INSTR_TBL_ROWSIZE	.equ	9
 
@@ -538,9 +538,9 @@ handleBITR:
 	ld	a, (curArg2)
 	ld	h, 0xb
 	call	findInGroup
+	ret	nz		; error
 	push	af		; push group value
 	; write first upcode
-	ret	nz		; error
 	ld	a, 0xcb		; first upcode
 	ld	(curUpcode), a
 	; get bit value
@@ -557,6 +557,73 @@ handleBITR:
 	ld	c, 2
 	ret
 
+handleIM:
+	ld	a, (curArg1+1)
+	cp	0
+	jr	z, .im0
+	cp	1
+	jr	z, .im1
+	cp	2
+	jr	z, .im2
+	; error
+	ld	c, 0
+	ret
+.im0:
+	ld	a, 0x46
+	jr	.proceed
+.im1:
+	ld	a, 0x56
+	jr	.proceed
+.im2:
+	ld	a, 0x5e
+.proceed:
+	ld	(curUpcode+1), a
+	ld	a, 0xed
+	ld	(curUpcode), a
+	ld	c, 2
+	ret
+
+handleLDIXn:
+	ld	a, 0xdd
+	jr	handleLDIXYn
+handleLDIYn:
+	ld	a, 0xfd
+handleLDIXYn:
+	ld	(curUpcode), a
+	ld	a, 0x36		; second upcode
+	ld	(curUpcode+1), a
+	ld	a, (curArg1+1)	; IXY displacement
+	ld	(curUpcode+2), a
+	ld	a, (curArg2+1)	; N
+	ld	(curUpcode+3), a
+	ld	c, 4
+	ret
+.error:
+	xor	c
+	ret
+
+handleLDIXr:
+	ld	a, 0xdd
+	jr	handleLDIXYr
+handleLDIYr:
+	ld	a, 0xfd
+handleLDIXYr:
+	ld	(curUpcode), a
+	; get group value
+	ld	a, (curArg2)
+	ld	h, 0xb
+	call	findInGroup
+	ret	nz		; error
+	or	0b01110000	; second upcode
+	ld	(curUpcode+1), a
+	ld	a, (curArg1+1)	; IXY displacement
+	ld	(curUpcode+2), a
+	ld	c, 3
+	ret
+.error:
+	xor	c
+	ret
+
 ; Compute the upcode for argspec row at (DE) and arguments in curArg{1,2} and
 ; writes the resulting upcode in curUpcode. A is the number if bytes written
 ; to curUpcode (can be zero if something went wrong).
@@ -791,6 +858,7 @@ argspecTbl:
 	.db	'A', "A", 0, 0, 0
 	.db	'B', "B", 0, 0, 0
 	.db	'C', "C", 0, 0, 0
+	.db	'k', "(C)", 0
 	.db	'D', "D", 0, 0, 0
 	.db	'E', "E", 0, 0, 0
 	.db	'H', "H", 0, 0, 0
@@ -918,7 +986,9 @@ instrTBl:
 	.db "EX",0,0, 'd', 'h', 0, 0xeb		, 0	; EX DE, HL
 	.db "EXX", 0, 0,   0,   0, 0xd9		, 0	; EXX
 	.db "HALT",   0,   0,   0, 0x76		, 0	; HALT
+	.db "IM",0,0,'n',  0,0x20 \ .dw handleIM	; IM {0,1,2}
 	.db "IN",0,0, 'A', 'm', 0, 0xdb		, 0	; IN A, (n)
+	.db "IN",0,0,0xb,'k',0x43, 0xed, 0b01000000	; IN r, (C)
 	.db "INC", 0, 'l', 0,   0, 0x34		, 0	; INC (HL)
 	.db "INC", 0, 'X', 0,   0, 0xdd , 0x23		; INC IX
 	.db "INC", 0, 'x', 0,   0, 0xdd , 0x34		; INC (IX+d)
@@ -954,6 +1024,10 @@ instrTBl:
 	.db "LD",0,0, 'A', 'M', 0, 0x3a		, 0	; LD A, (NN)
 	.db "LD",0,0, 'M', 'h', 0, 0x22		, 0	; LD (NN), HL
 	.db "LD",0,0, 'h', 'M', 0, 0x2a		, 0	; LD HL, (NN)
+	.db "LD",0,0, 'x','n',0x20 \ .dw handleLDIXn	; LD (IX+d), n
+	.db "LD",0,0, 'y','n',0x20 \ .dw handleLDIYn	; LD (IY+d), n
+	.db "LD",0,0, 'x',0xb,0x20 \ .dw handleLDIXr	; LD (IX+d), r
+	.db "LD",0,0, 'y',0xb,0x20 \ .dw handleLDIYr	; LD (IY+d), r
 	.db "NOP", 0, 0,   0,   0, 0x00		, 0	; NOP
 	.db "OR",0,0, 'l', 0,   0, 0xb6		, 0	; OR (HL)
 	.db "OR",0,0, 0xb, 0,   0, 0b10110000	, 0	; OR r